THE AMERICAN SOUTH-CENTRAL — THE ADVISORY FOOTPRINT SHRANK TO ABOUT FOUR, THE CORE DID NOT

On the board · September 20, 2026 →

EASING · September 20, 2026 · NO. 0920

THE DOME

The map shrank; the core did not. Heat Advisories read about 4, down from 13 the previous morning — Kentucky, Indiana, Middle Tennessee, southern Illinois and south-east Missouri plus Puerto Rico and the US Virgin Islands — with the index still to about 108 °F in Middle Tennessee. The short-range discussion has the heat moderating northward while the core holds over the central and southern Plains, the Tennessee Valley and the lower Mississippi Valley.

THE RECORD

54 turning points on record since Jun 9 — the 8 most recent shown.

Sep 19↑ moved up the board

Sep 18↑ firmed

Sep 17active → building

Sep 16▽ slipped down the board

Sep 15▽ eased

Sep 13easing → active

Sep 12↑ moved up the board

Sep 11building → easing · eased sharply

WHO IT TOUCHES

Eventsa national holiday weekend under a rain shield, hail over outdoor operations, and a shrinking but real heat index

Healtha heat index that is still dangerous on a smaller map, and three flood recoveries where the health risk outlives the water

Energyan easing but still loaded evening peak, a distribution network under a holiday rain shield, and a river that constrains fuel movement

CONNECTED

One airmass retreating is the other's forecast — the hot core and the hail risk sit on opposite sides of the same boundary.